Applying coupon-collecting theory to computer-aided assessments

Computer-based tests with randomly generated questions allow a large number of different tests to be generated. Given a fixed number of alternatives for each question, the number of tests that need to be generated before all possible questions have appeared is surprisingly low.Comment: 19 pages; bibliographic information added as follows. To appear in Bingham, N. H., and Goldie, C. M. (eds), Probability and Mathematical Genetics: Papers in Honour of Sir John Kingman. London Math. Soc. Lecture Note Series. Cambridge: Cambridge Univ. Pres

Practical Flexibility Tests for Use in the Health and Fitness Setting

No abstract is provided

Prefrontal Leucotomy in Chronic Psychosis

(1) The results of prefrontal leucotomy are reported in 68 cases of chronic mental illness which had failed to respond to all other methods of treatment. The patients are still resident in a mental hospital after a postoperative period ranging from one to 4 years. 44 patients improved in varying degree and 24 are considered to he unimproved. (2) The results are analysed in terms of age, sex, duration of the illness, diagnostic classification and the operative technique employed. The form taken hy amelioration in the various illnesses is described and examples of the postoperative state are given. (3) Post-operative signs occurring in all leucotomlsed patients in hospital at the time of the survey are listed. Other early effects of leucotomy include favourable results in 2 cases of obsessional neurosis outwith the present series. The main post-operative signs are euphoria, an elevation of mood to a lesser degree and inertia. These are signs of frontal lobe deficit and their recurrence in relation to improvement in the 68 patients is charted, and their effect in modifying the psychosis described. No relationship is found between premorbid and postoperative personality traits. (4) After-treatmentis described and the value of postoperative electroplexy and of re-operation is discussed. (5) Relapse occurred transiently in 16 and permanently in 12 patients. Its theoretical aspects are discussed. (6) Changes in body-weight following leucotomy are described. No correlation is found between increased weight and improvement of mental symptoms. (7) Two factors in the pre-operative state thought to influence the prognosis are examined in relation to post-operative improvement. Those cases which improved after leucotomy had in aggregate a greater degree of mental tension than those not improving. No such prognostic significance could be attached to the other factor, the degree of break with reality. (8) Theories of the operation are examined in the light of the results. It seems most likely that the operation acts by superimposing a modified frontal lobe syndrome on the psychosis. The importance of the position of the cut is suggested. No relationship is found between orbital area isolation and post-operative changes in the emotional sphere. (9) The lack of finality in the reported results is mentioned. They are compared with the results published by others. The significance of the result "worse" is discussed. It is concluded that affective and obsessional illnesses respond well to leucotomy. The results in schizophrenia are less satisfactory, hut in this illness the greatest response is found in the catatonic and paranoid types, the least in the hebephrenic variety. Leucotomy acts by the removal of mental tension and where this is marked there is still hope of improvement, even if the patient is considered deteriorated. It is further concluded, that while duration is less and tension greater where the response to the operation is good, there is no common factor in those patients who improve or fail to improve after leucotomy. The results in individual cases of chronic mental illness are unpredictable before operation, but the value of this method of treatment in such cases is fully confirmed

Bootstrapping for text learning tasks

Journal ArticleWhen applying text learning algorithms to complex tasks, it is tedious and expensive to hand-label the large amounts of training data necessary for good performance. This paper presents bootstrapping as an alternative approach to learning from large sets of labeled data. Instead of a large quantity of labeled data, this paper advocates using a small amount of seed information and a large collection of easily-obtained unlabeled data. Bootstrapping initializes a learner with the seed information; it then iterates, applying the learner to calculate labels for the unlabeled data, and incorporating some of these labels into the training input for the learner. Two case studies of this approach are presented. Bootstrapping for information extraction provides 76% precision for a 250-word dictionary for extracting locations from web pages, when starting with just a few seed locations. Bootstrapping a text classifier from a few keywords per class and a class hierarchy provides accuracy of 66%, a level close to human agreement, when placing computer science research papers into a topic hierarchy. The success of these two examples argues for the strength of the general boot¬ strapping approach for text learning tasks

Dominican Women across Three Generations: Educational Dreams, Goals and Hopes

This study explores the struggle of Dominican women to access formal education and the impact of such access in their lives and on their own perceptions of their experiences. The essay captures the voices of female members of three generations of Dominican immigrant families in New York City

Learning dictionaries for information extraction by multi-level bootstrapping

Journal ArticleInformation extraction systems usually require two dictionaries: a semantic lexicon and a dictionary of extraction patterns for the domain. We present a multilevel bootstrapping algorithm that generates both the semantic lexicon and extraction patterns simultaneously. As input, our technique requires only unannotated training texts and a handful of seed words for a category. We use a mutual bootstrapping technique to alternately select the best extraction pattern for the category and bootstrap its extractions into the semantic lexicon, which is the basis for selecting the next extraction pattern. To make this approach more robust, we add a second level of bootstrapping (metabootstrapping) that retains only the most reliable lexicon entries produced by mutual bootstrapping and then restarts the process. We evaluated this multilevel bootstrapping technique on a collection of corporate web pages and a corpus of terrorism news articles. The algorithm produced high-quality dictionaries for several semantic categories

Detections of massive stars in the cluster MCM2005b77, in the star-forming regions GRS G331.34−-00.36 (S62) and GRS G337.92−-00.48 (S36)

Large infrared and millimeter wavelength surveys of the Galactic plane have unveiled more than 600 new bubble HII regions and more than 3000 candidate star clusters. We present a study of the candidate clusters MCM2005b72, DBS2003-157, DBS2003-172, and MCM2005b77, based on near-infrared spectroscopy taken with SofI on the NTT and infrared photometry from the 2MASS, VVV, and GLIMPSE surveys. We find that (1) MCM2005b72 and DBS2003-157 are subregions of the same star-forming region, HII GRS G331.34-00.36 (bubble S62). MCM2005b72 coincides with the central part of this HII region, while DBS2003-157 is a bright mid-infrared knot of the S62 shell. We detected two O-type stars at extinction \Aks=1.0-1.3 mag. Their spectrophotometric properties are consistent with the near-kinematic distance to GRS G331.34-00.36 of 3.9pm0.3 kpc. (2) DBS2003-172 coincides with a bright mid-infrared knot in the S36 shell (GRS G337.92-00.48), where we detected a pair of candidate He I stars embedded in a small cometary nebula. (3) The stellar cluster MCM2005b77 is rich in B-type stars, has an average Aks of 0.91 mag, and is adjacent to the HII region IRAS 16137-5025. The average spectrophotometric distance of $\sim 5.0$ kpc matches the near-kinematic distance to IRAS 16137-5025 of 5.2pm0.1 kpc.Comment: 22 pages, 11 Figures, ApJ accepte

Star Clusters in Virgo and Fornax Dwarf Irregular Galaxies

We present the results of a search for clusters in dwarf irregular galaxies in the Virgo and Fornax Cluster using HST WFPC2 snapshot data. The galaxy sample includes 28 galaxies, 11 of which are confirmed members of the Virgo and Fornax clusters. In the 11 confirmed members, we detect 237 cluster candidates and determine their V magnitudes, V-I colors and core radii. After statistical subtraction of background galaxies and foreground stars, most of the cluster candidates have V-I colors of -0.2 and 1.4, V magnitudes lying between 20 and 25th magnitude and core radii between 0 and 6 pc. Using H-alpha observations, we find that 26% of the blue cluster candidates are most likely HII regions. The rest of the cluster candidates are most likely massive (>10^4 Msol) young and old clusters. A comparison between the red cluster candidates in our sample and the Milky Way globular clusters shows that they have similar luminosity distributions, but that the red cluster candidates typically have larger core radii. Assuming that the red cluster candidates are in fact globular clusters, we derive specific frequencies (S_N) ranging from ~0-9 for the galaxies. Although the values are uncertain, seven of the galaxies appear to have specific frequencies greater than 2. These values are more typical of ellipticals and nucleated dwarf ellipticals than they are of spirals or Local Group dwarf irregulars.Comment: 46 pages, 14 figures, 3 tables, accepted by AJ. Higher quality PS version of entire paper available at http://www.astro.washington.edu/seth/dirr_gcs.htm